lewis



June 10, 1930. w.- LEWIS I 1,7 3, 8

PISTON AND CYLINDER CONSTRUCTION FOR MOLDING MACHINES Filed Feb. 5, I928 2 Sheets-Sheet 1 June 10,1930. v w; LEWIS 6 ,0

PISTON AND CYLINDER GONSTRUCTION'FOR MOLDING MACHINES Patented June 10, 1930 UNETED STATES f1; A C g WILFRED LEWIS, on HAVERFORD, PENNSYLVANIA, ASSIGNOR TO THE TABOB, MANU:

FACTURING' COMPANY, OF PHILADELPHIA, PENNSYL'V'ANTA, A CORPORATION OF PENNSYLVANIA I PISTON AND CYLINDER cons'rnucrron non MOLDING-MACHINES Application filed February 'QNONZ5L7V28.

Many molding machines include in their construction a rollover table, and the present 1nVent1on1s a means for rolling over the table with a quick motion at the intermediate portion of its travel and with a relatively slow motion at the end of its travel to the end that the operation of the machine can be speeded up without shocks.

The invention is applicable to various types of machines and it will be claimed at the end hereof.

In describing the invention reference will be made to the accompanying drawings forming part hereof and illustrating one application of the invention, and in those drawings Figure 1 is an end elevational view partly in section of parts of a molding machine embodying piston and cylinder construction of the invention. V

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1.

Fig. 3 is a central sectional view drawn to an enlarged scale of. piston and cylinder construction embodying features of the invention, and V Fig. 4 is a partial section taken in a plane at right angles to the plane of Fig. 3.

In the drawings 2 is an oil cylinder and. 1 is an oil piston, and there is'packing 20 at the end of the piston and packing 21 at the end of the cylinder. These together with the provision of space between the piston and cylinder provide a chamber 7' between them.

There is a bypass 9 having ports through the cylinder wall and whereof one,10, is located to be covered by the piston in its innermost position,'and whereof the other, 8, is'loca ted below the top of the chamber 7 to provide space 11 for trapping oil to check the outstroke of the piston. 15 is a vent openlng through the piston wall and it is arranged above the packing 20 thereof to permit slight leakagein order to afford adjustment of the outstroke for a purpose that will be presently described. 14 is a relief passage having a check valve 22 and extending from near the bottom of the cylinder to the top ll'of the chamber 7 to permit instroke of the piston. 23 indicates a rollover'table, and a rack 12, meshing with a gear 24 on the trunnion of the rollover table, serves onthe outstroke of piston, to invertt'he table. The cylinder 2, is

pivotally mounted at 16 in the housing 18.

The mode of operation of the described parts' in association with other parts, which willbe referred to, may be, described as. follows ' The piston 1 and, cylinder2 are filled with thin hydraulic oil through the filling plug hole 3 to thelevel of line H in Figure 3 and air is admitted to the piston through the air pipe' i and; forces the oil out'through holes 5 in the baffle cap 6 raising the piston. Oil is trapped in chamber'7, port Sand by-pas's 9 H and creates a" certain amount of starting .re- 'sistance.'Th1s oil escapes ethrough port 15 upward movement of the piston Asthe piston 1 travels up the oil that fills into theinterior of piston lpermittingthe and serves to" prevent shock when thestop contact with a corresponding st op26 onthe housing; The vent 11019515- i n the piston 1 permits thetahle 23 to berolled against stops 26 at a'reduced'sp'eedjwithout appreciable bolt 25 on the rollover table 231comesinto shock by reason of the oil escaping slowly from the space 11 through the port 15.

The gear rack 12 carries a spring 13 which QM 1s compressed at the top end of the travelof piston 1. When air is exhausted-from the piston 1 the spring 13 reacts to push the piston 1 downf WVhe-n the piston moves down oil is admitted to the cushion chamber 11 from the bottom of the'cylinder 2 through the relief pipe 14, and'check valve 22. Also oil returns through the holes 5 and is prevented from spraying by thebaflie plates 6.

58'is an adjusting screw for the. purpose of sustaining the weight of the piston and rack so that their weight will not shift the position of theftrunnion gear shaft 59 when the rollover table is lifted out of the trunnion shaft during the jarring operation. 60 is a i flexible air hose connection from a pipe line and leading to a valve stand.

It will be obvious to those skilled in the art to which the invention relates that modifications may be made in details of construc tion and arrangement and matters of mere form without departing from the spirit of the invention which is not limited to such matters or otherwise than theprior art and the appended claims may requlre.

I clann: 1. A rollover inechanlsm for molding machines coinp rising; an oil cylinder and piston having packing at the end of the piston and at the top of the cylinder to-prov-i'de a cliamber between them abypass having ports through the cylinder Wall whereofone is located tobe covered by the piston in its innerm'os t position and whereof the other is locate'd below the top ofsaid chamber to provide spacefbr trapping oil'to check the oiitstrolieof-the'piston, a vent opening through the piston Wall arranged'near the packing thereof to permit the trapped oil to escape slowly While:the plStOII'IDOVQS'UPTO the end ofits'traVel; a. relief: passage h'a-Vin'gja check valve and extending from near the bottom of thecylinder to the'to'p of said chamber to 'permitin'stroke of the piston, and a spring for initiating the" insti'ok e'.

2.- A rollovertmechanism formolding machines comprising 'an oil'cylin'der and piston h'avingpacking'at the end'of the piston and at the top of thec'ylinder' to provide a chamber between them, a bypass having ports through the cylinder Wall whereof one is locate'dto be'c'overed by'the piston in its innermost position and whereof the other is located below the top of said chamber to provide space for trapping oil to" check the outstroke ofth'episton, a relief passage haviirgfa check valvean'd extending from near tli ebottom' of thecylinder-to the top of said chamber to permitinstroke of the piston, and

aspring for initiating the instroke.

WILFRED LEXVI'S- 

